The primary function of interior walls, partitions and doors is to divide building space into separate, private spaces. In construction, there have been, over the past 5-10 years increasing demands for and efficiencies in the development of closed spaces which are sound insulated. With regards to walls, when additional thermal and/or acoustic insulation is needed, insulation medium such as fibreglass, rock wool or mineral wool will commonly be placed to fill the interior space between vertical studs and gypsum board panels. Sound transmission through walls can be reduced by widening the wall and staggering the studs such that no stud spans the full width of the wall.
For the occupants of such spaces, while reduction in sound transmission and heat/AC efficiencies are important, even more important planning aspects relating to health and comfort. Excellent air quality is especially essential and can only be achieved if “used” air is regularly replaced by new or fresh air. If a space becomes essentially “airtight”, this air exchange does not adequately occur without costly “active” ventilation methods.
Passive ventilation allows rooms to ventilate while windows and doors are closed. This reduces condensation and provides a healthy air exchange. Passive ventilation may be achieved by either the installation of transfer ducts in the ceiling or walls between two closed spaces and/or the installation of grills in or around a doorway. In regards to ducts, these must be custom sized and installed on site during building construction or during a major renovation. With regard to grills, these are seen as aesthetically displeasing. An example of an after-market grill to retrofit on standard doors is made by Tamarack Technologies Inc. A drawback of all such door grills is the lack of acoustic privacy. The grill simply provides a thoroughfare air channel from one space (for example a corridor) to another space (for example, an office). Neither privacy nor sound attenuation is considered with regard to these grills.
There remains a need for a passive ventilation system which attenuates sound and which can adequately address these and other challenges.
It is an object of the present invention to obviate or mitigate the above disadvantages.